<!doctype html>
<html>
<head>
    <meta charset="UTF-8">
    <meta name="viewport"
          content="width=device-width, user-scalable=no, initial-scale=1.0, maximum-scale=1.0, minimum-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
    <style>
        body{
            margin: 0;
            padding: 0;
        }
        #box{
            width:500px;
            height:500px;
            border:1px solid black;
            background:radial-gradient(circle at 50% 50%,white 0,pink 0,pink 30%,transparent 30%);
            cursor: pointer;
            transition: 1s;
        }
        #box.show{
            width:500px;
            height:500px;
            border:1px solid black;
            background:
                    radial-gradient(circle at 15% 15%,white 0,orangered 0,orangered 12%,transparent 12%),
                    radial-gradient(circle at 85% 85%,white 0,orangered 0,orangered 12%,transparent 12%),
                    radial-gradient(circle at 85% 15%,white 0,orangered 0,orangered 12%,transparent 12%),
                    radial-gradient(circle at 15% 85%,white 0,orangered 0,orangered 12%,transparent 12%);
        }


    </style>
</head>
<body>
<div id = box>
</div>
<script>
    let box = document.querySelector("#box")
    box.onclick = function (){
        box.className = "show"
    }
</script>
</body>
</html>